Polishing wheel



April 16, 1968 c. G. PECK 3,377,753

POLISHING WHEEL Filed Jan. 7. 1965 INVENTOR Garza? 6? Pack ATTORNEYSUnited States Patent This invention relates generally to polishing orfinishing wheels of the type comprising a plurality of radiallydirected, abrasive-bearing sheets secured together at their radiallyinner ends to define a generally cylindrical hub, and arranged to bemounted on a driven shaft. More particularly, it relates to a polishingwheel of the type described, designed so that a plurality thereof can beas sembled in side'by-side relationship to provide a polishing wheelassembly which will have a greater number of abrasive-bearing sheets onthe periphery thereof than is possible on a single polishing orfinishing wheel of like construction and diameter.

Abrasive polishing and finishing devices of many types have been devisedfor use on metals, wood and other materials to provide finished surfacesfree from imperfections. Among the abrasive devices which have been usedare abrasive coated cloth or paper, utilized in the form of either awheel or a moving belt, loose abrasive applied to a set-up wheel, andabrasive-impregnated grinding wheels. These and other like abrasivedevices have been used on hand tools, jack stands, back-up stands, swingframe grinders, automatic grinding wheels, fiat polishing machines, andother like apparatus.

Experience has shown that various diiliculties are sometimes connectedwith the use of many commonly employed abrasive polishing and finishingdevices. For example, a set-up wheel frequently is not uniform in theloading of abrasive, and at times will place deep scratches in thesurface being finished. The abrasive-coated belt, for another example,suffers the disadvantage that in use the abrasive soon becomes loadedwith removed material, and thus loses its cutting ability; further, asthe abrasive on the belt becomes loaded with removed material, excessiveheating frequently results which, in turn, tends to burnish the worksurface.

A polishing wheel formed from a plurality of radially directed,abrasive-bearing sheets of cloth or the like is one of the mostdesirable and effective abrasive devices for polishing or finishing manymaterials. The sheets are secured together at their inner ends to definea generally cylindrical hub, and the resultant wheel is mounted upon adriven shaft. Such a polishing wheel when used on steel and othermetals, for example, removes a minimum of metal in producing a finishedsurface and has little or no tendency to scratch the work surface. Inaddition, the abrasive on such a polishing wheel does not tend to become loaded with removed metal, and the operating temperature thereofis, consequently, lower than for an abrasive belt.

The effectiveness of a polishing wheel such as that just described isprimarily dependent upon the amount of abrasive that comes into contactwith the work surface. In the past, the only way in which effectivenessof such a polishing wheel could be improved was to increase either thespeed of revolution or the diameter of the wheel, or both, both of whichhave certain disadvantages.

In a polishing wheel made up of a plurality of radially directed sheetsjoined together at their inner ends to define a generally cylindricalhub, it is evident that for any given internal hub diameter and anygiven sheet thickness, only a certain, predetermined number of sheetscan be mounted on the wheel. It is because of this inherent limitationon the number of sheets which can be assembled into a polishing Wheelthat it has been necessary, until this invention, to increase the speedof rotation and/ or ice the diameter of the wheel to obtain a. desiredincrease in the amount of abrasive which engages the work surface.

According to the present invention, however, the previous inherentlimitation to the number of sheets mounted on the periphery, or worksurface engaging portion, of a polishing wheel has been overcome,whereby the number of abrasive-bearing sheets at the periphery of apolishing Wheel assembly can be, at least, doubled. This inventionprovides a polishing wheel assembly of greatly increased aggressiveness,or cutting ability, over heretofore known polishing wheel assemblies ofthe same size operated at the same speed of rotation. Further, bygreatly increasing the number of sheets at the outer periphery, thepolishing wheel assembly provided by the invention is made more densethan heretofore possible, which also enhances aggressiveness, or cuttingability. The polishing wheel assembly of the invention compares ineffectiveness with an abrasive belt in removing metal, but avoids thehereinabove described undesirable characteristics of such belts.

In its simplest form, the polishing wheel assembly of the inventioncomprises a pair of polishing wheels mounted in side by side, abuttingrelationship. Each wheel is comprised of a plurality of radiallydirected, abrasive-bearing sheets connected together at their inner endsto define a generally cylindrical hub. The sheets are wider at theirouter portions than they are at the hub, usually by a factor of 2, andthe radially outer portions of each wheel project toward the other Wheeland are interleaved, preferably alternately, with the sheets on theother wheel. The result is a polishing wheel assembly having twice asmany sheets on the radially outer, or work surface engaging, portionthereof than has previously been possible.

The polishing wheel assembly of the invention can be employed on handtools, swing grinders, and all manner of polishing and finishingdevices. Moreover, the assembly need not be limited to two wheels inside-by-side relationship but may be extended to include a greaternumber of individual polishing wheels.

A polishing wheel assembly made up of a large number of individualpolishing wheels, made according to the teachings of the invention, canbe readily utilized for a wide, flat polishing operation. At present,such an operation is normally performed by a wide, abrasive-coated clothor paper belt, which is driven over a rubber covered contact roll thatis mounted in a fixed position and is only free to revolve. Directlybelow the rubber covered roll is a billy roll, usually of steel, whichhas as its purpose to exert pressure against the underside of thematerial that is to be polished to cause the top surface of suchmaterial to contact the abrasive-coated belt. Abrasive-coated belts forthis purpose, like other abrasivecoated belts, tend to load up withremoved material and, thus, lose their effectiveness.

It is usually not desirable to assemble a number of ordinary polishingwheels in side-by-side relationship to form an elongated polishing wheelto do wide surface polishing, as the joints between the polishing wheelswill result in lines or streaks on the work surface. Further, because ofmechanical problems, it is normally not possible to make a single,conventional polishing wheel with an axial length sufficiently long sothat :a single polishing wheel can do the job. An elongated polishingWheel assembly for wide surface polishing can be made up according tothe teachings of the present invention, however, and such an assembly issuperior both in performance and life expectancy to the conventionalabrasive-coated belt.

In this embodiment of the invention, a pair of the novel polishingwheels described above are employed at the ends of the assembly, withtheir wider, radially outer sheet portions projecting towards eachother. Disposed between these end wheels is one, or more, otherpolishing wheel having outer peripheral sheet portions which projectaxially of the wheel beyond both end faces of its hub, all of the wheelshaving the same external diameter. All of the radially outer sheetportions on all of the polishing wheels are interleaved, and theresultant polishing wheel assembly, which is, in effect, an elongatedroll of uniform diameter and with an unbroken surface, will effectivelyremove material without becoming loaded with removed material, andwithout leaving streaks or lines.

Because the abrasive-coated sheets in polishing wheel assemblies madeaccording to the present invention are interleaved with each other,there are no joints or other discontinuties between the wheels. Thisfeature prevents the formation of streaks or lines when several of thepolishing wheels of the invention are assembled for Wide surfacepolishing. The wheels are usually held in interleaved relationship byclamping the opposite ends of the assembly, although the frictionalengagement between the interleaved sheets also holds the wheelsassembled. To further insure that the outer sheet portions will notshift relative to each other during use, the inner portions of theinterleaved sheets can be secured together by use of a suitableadhesive.

It is the object of the present invention to provide a polishing wheelincluding a plurality of radially directed, abrasive-bearing sheetssecured together at their inner ends, and constructed so that aplurality thereof can be assembled in side-by-side, abuttingrelationship to provide a polishing wheel assembly having asubstantially greater number of abrasive-bearing sheet portions on theperiphery thereof than has heretofore been possible for a similarpolishing wheel assembly of like size.

Another object is to provide a polishing wheel including a plurality ofradially directed, abrasive bearing sheets, and constructed so that aplurality thereof can be assembled in side-by-side relationship toprovide an elongated polishing wheel assembly for wide surface polishingwhich will not streak or line the work surface.

A further object is to provide a polishing wheel assembly which will bemore dense and aggressive for a given diameter and speed of rotationthan present wheels of like size operated at like speeds, and which iseconomical to construct and possessed of a relatively long lifeexpectancy.

Other objects and many of the attendant advantages of the presentinvention will become readily apparent from the following detaileddescription, when taken in consideration with the accompanying drawings,wherein:

FIG. 1 is a side elevational view, partially broken away, of a polishingwheel assembly constructed according to the invention;

FIG. 2 is a vertical, sectional view taken along the line 2-2 of FIG. 1;

FIG. 3 is a vertical sectional view of a modified embodiment of theinvention, wherein a plurality of polishing wheels are assembledtogether to form an elongated polishing wheel assembly;

FIG. 4 is a perspective view of one of the sheets of one of the wheelsof FIG. 1; and

FIG. 5 is a perspective view of one of the sheets from the middle wheelof the polishing wheel assembly of FIG. 3.

The polishing wheels of the invention are made from a suitable cloth,paper or other sheet material, which has been coated on one or bothsides with an abrasive of suitable coarseness. The manner in which suchabrasivecoated sheets are manufactured is known, and such does notconstitute a part of this invention. Preferably, when the material ofthe sheets is cloth, the invidiual sheets for the polishing wheels ofthe invention are cut on the bias, to prevent tearing and shredding whenin use. The

abrasive-bearing sheets of the wheel can be of the kind which are leftdry when engaged with material to be finished, or they can be of thekind to which Water, oil, or other liquids are applied when in use.

Referring now to the drawings, a first embodiment of the polishing Wheelassembly of the invention is shown in FIGS. 1 and 2, and comprises apair of polishing wheels 2 and 4. The wheels 2 and 4 are constructed inan identical manner, and hence a description of one will sullice forboth.

The polishing wheel 2 comprises a plurality of abrasivecoated sheets orleaves 6, all of uniform thicknes throughout, the configurations of allwhich are identical. Each of the sheets 6 includes a radially inner, orhub, portion 8, and a radially outer portion 10. The radially inner orhub portions 8 of the sheets 6 have aligned bores 12 therein, withinwhich is received an annular core 14, which can be made from steel orsome other suitable material. The sheets have slits 15 in their inneredges leading to the bores 12, to facilitate assembly on the ring orcore 14. The sheets 6 are first assembled onto the annular core 14, andthe radially inner portions 8 thereof are then secured together by asuitable adhesive (indictaed at 16 in FIG. 1 for the polishing wheel 4)to define a generally cylindrical hub 13.

The opposite end faces 20 and 22 of the cylindrical hub 18 of thepolishing wheel 2 are radial and extend parallel to each other, and eachend face has an annular groove 24 therein. The axially outer side edges26 of the sheets 6 lie in the same radial plane as the associated hubend face 2i). The inner diameter of the hub 18 is relatively large, andit is apparent that the number of sheets 6 which can be assembled intothe polishing wheel 2 is limited by said inner hub diameter and by thethickness of the sheets 5. For any given thickness of the sheets 6, asthe inner diameter of the hub 18 is increased the number of sheets 6 inthe wheel 2 can be correspondingly increased, and vice versa.

The radial outer portions 10 of the sheets 6 are substantially widerthan the axial length of the hub 18. Preferably, the outer sheetportions 10 will have a width equal. to the combined axial length of thehub 18 and the hub of a mating polishing wheel; assuming both such hubsare identical, then the width of the outer sheet portions 16 will betwice the axial length of the hub 18. The axially inner edge 28 of eachsheet 6 includes an outer radial portion 30 which extends parallel tothe sheet edge 26, and an angled portion 32, which extends to the endface 22 of the cylindrical hub 18 at an angle of about degrees.

Each of the sheets 6, thus, includes a portion 33 which projectsoutwardly from the hub end face 22 a distance preferably equal to theaxial length of the hub of a mating polishing wheel. The projectingportions 33 are configured to be fully received between the sheets on amating polishing wheel.

The polishing wheel 2 is intended to be mounted upon a driven shaft 34,and for this purpose n'zetal end plates 36 are mounted on the hub endfaces fill and 22. The end plates 36 have annular ribs 38 thereon, whichribs are received within the annular grooves 24 in their associated endfaces 26 or 22. The annular ribs 33 and the grooves 24 function toretain the end plates 36 concentrically on the hub end faces 20 and 22,and also help to secure the radially extending sheets or leaves 6against radial displacement.

The shaft 34 includes a reduced diameter portion 4%, terminating at itsinner end in a radial shoulder 42. The end plates 36 have centrallypositioned bores 44 therethrough of a diameter just slightly larger thanthat of the reduced shaft portion re, and the wheel 2 can, thus, bemounted with the outer end plate 36 in engagement with the shoulder Theouter end of the shaft 3 has threads 46 thereon, and a securing nut 48and a washer 49 are received thereon.

The polishing wheel 4 is identical to the polishing wheel 2, andincludes a plurality of radially extending sheets or leaves 50 securedtogether at their radially inner ends by adhesive 16 (FIG. 1) to definea cylindrical hub 52. The opposite end faces 54 and 56 of the hub 52have annular grooves 58 therein, and end plates 60 having annular ribs62 thereon are mounted on said end faces. The inner ends of the sheets50 have centrally positioned bores 64 therethrough for receiving anannular core ring 66.

The sheets 50 include radially outer portions 68, which aresubstantially wider than the axial length of the cylindrical hub 52. Theaxially outer side edges 70 of the sheets 50 lie in the same radialplane as the end face 54 of the cylindrical hub 52, and the inner sideedge of each sheet 50 includes an outer portion 72 that extends parallelto the outer side edge 70, and an angled portion 74. The sheets 50,thus, include axially projecting portions 75 corresponding to theportions 33 on the sheets 6, the portions 75 preferably projecting fromthe hub end face 56 a distance equal to the axial length of the hub onan adjacent polishing wheel.

It will be noted that the polishing wheels 2 and 4 are, in fact,identical when the sheets thereof are coated on both sides with anidentical abrasive. When mounted on the shaft 34 to form a polishingwheel assembly, however, the wheels 2 and 4 are mounted so that theouter side edges 26 and 70 face oppositely and so that the sheetportions 33 and 75 project toward each other.

If the sheets of the wheels 2 and 4 are coated with abrasive on only oneside, or with different abrasives on opposite sides, then separate rightand left hand wheels must be made.

To make a polishing wheel assembly according to the invention, thepolishing wheel 2 is first mounted on the shaft 34-, which shaft isconnected to suitable driving apparatus. The polishing wheel 4 is thenmoved onto the shaft 34, and the projecting sheet portions 33 and 75 arethen interleaved, preferably in an alternate manner, with the sheets onthe opposite polishing wheel. The two polishing wheels 2 and 4 are thenmoved axially together until the confronting end plates 36 and 60 are inabutting engagement. Referring in particular to FIG. 2, it will be notedthat when the polishing wheels 2 and 4 are thus assembled, theinterleaved radially outer sheet portions on the two wheels will becoextensive, so that there will be twice the number of individual sheetportions, or leaves, on the periphery of the polishing wheel assemblythan at either of the cylindrical hubs 18 and 52. said outer sheetportions extending axially for the combined lengths of said hubs.

Referring to FIG. 1, it will be noted that whereas the inner ends ofadjacent radially directed sheets 50 on the wheel 4 (the same being truefor the sheets 6 on the wheel 2) are in direct contact, said adjacentsheets are separated at the periphery of the polishing wheel 4. The gapor space between adjacent sheets 50 or 6 is tapered from the cylindricalhubs 18 or 52 on the wheels toward the outer periphery of said wheels.It is because this tapered space is inherently present between the outerportions of the radially directed sheets 6 and 50, which are of uniformthickness throughout, that it is possible to construct a polishing wheelassembly according to the invention. The projecting portions 33 and 75on the radially outer portions of the sheets 6 and 50 in the inventionare readily receivable in the spaces between adjacent sheets on theopposite wheel, and the resultant polishing wheel assembly issubstantially more dense and less flexible than is true of either thewheel 2 or the wheel 4 individually. The result is that theaggressiveness or cutting ability of the polishing wheel assembly shownin FIG. 2 is substantially greater than that of the individual polishingwheels 2 and 4.

In FIG. 2, the inner edge outer portions 30 on the sheets 6 are notshown to extend completely to the outer edges on the sheets 50, nor arethe .inner edge outer portions 72 on the sheets 50 shown to extendcompletely to the outer edges 26 on the sheets 6. It is to be understoodthat this has been done in the drawings only for purposes of clarity,and that in an actual embodiment it is preferable that the outerportions of the sheets 6 and 50 be completely coextensive when thepolishing wheels 2 and 4 are in assembled relationship.

The polishing wheel assembly of FIG. 2 is suitable for use on small orindividual workpieces, and because the number of abrasive-bearing sheetson the periphery thereof is substantially twice that which has beenpreviously obtainable in polishing wheels, the agressiveness or cuttingability thereof is greatly increased. However, the polishing wheelassembly of FIG. 2 still retains the desirable characteristics ofpolishing wheels of this type, in that the abrasive on the sheets willnot become unduly loaded with removed material, and operating temperatures will not exceed acceptable limits.

The concept of the invention also includes the making of an elongatedpolishing wheel assembly having an unbroken external surface, for use infinishing wide surfaces. Such an elongated polishing wheel assembly isshown in FIG. 3, wherein is illustrated a shaft 76 including a reduceddiameter portion 78 that terminates at its outer end in a threadedportion 80. Mounted on the reduced diameter shaft portion 78, in axiallyspaced relationship, are a pair of polishing wheels 2 and 4. Positionedbetween the polishing wheels 2 and 4 on the shaft portion 78 is a thirdpolishing wheel 82, comprising a plurality of radially directed sheets84 secured together at their inner ends by suitable adhesive (not shown)to define a cylindrical hub 86. The inner ends of the sheets 84 havebores 88 therethrough for the reception of an annular core ring 90, andthe axial end faces 92 and 94 of said hub 86 extend radially and haveannular grooves 96 therein. End plates 5 8, having annular ribs 100there on, are mounted on the end faces 92 and 94, and are employed tomount the polishing wheel 82 on the shaft portion 78. All of the wheels2, 4 and 82 are identical in external diameter.

The axial length of the cylindrical hub 86 is equal to the combinedaxial lengths of the cylindrical hubs 18 and 52. The radially outerportions 102 of the sheets 84 have a width equal to about twice theaxial length of the hub 86, and the opposite, radially outer side edgeportions 104 and 106 thereof are parallel, and are spaced equaldistances axially outwardly from their associated hub end faces 92 and94 to define axially projezting sheet portions 105 and 107. The radiallyouter edge portions 104 and 106 are connected to their associated endfaces 92 and 94 by angled edge portions 108 and 110, respeetiiely, whichextend at an angle of about 45 degrees.

The polishing wheel assembly of FIG. 3 is made up by first putting thepolishing wheel 2 on the shaft port on 78. The polishing wheel 82 isthen placed on said shaft portion, and the projecting sheet portions 107on the polishing wheel 82 are then interleaved, preferably in analternate manner, with the sheets 6 on the polishing wheel 2. Thepolishing wheels 82 and 2 are then moved axially together until theconfronting end plates 36 and 98 are in abutting engagement. Thepolishing wheel 4 is then placed on the shaft portion 76, and theprojecting sheet portions thereof are then interleaved, preferably in analternate manner, with the sheets 84 on the pol'sh ng whecl 82. Thepolishing wheel 4 is then moved axially toward the polishing wheel 82until the confronting end plates 60 and 98 are in abutting engagement. AWasher 112 and nut 114 are then placed on the threaded outer end portionof the shaft 76, to secure the polishing wheels of the assembly inplace.

In the polishing wheel assembly of FIG. 3, like in the polishing wheelassembly of FIG. 2, the radially outer portions of the sheets 6, 50 and84 are not shown to be coextensive for purposes of clarity, although inan actual embodiment said sheets would be coextensive and the edgeportions 30 and 72 of the sheets 6 and 50, respectively, on thepolishing wheels 2 and 4 would be in engagement. While only onepolishing wheel 82 is shown in H6. 3, it is understood that any numberthereof could be placed between the polishing wheels 2 and 4 to providea polishing wheel assembly of substantially any desired axial length,assuming a shaft 76 of the necessary length ani with a diametersutficient to provide the necessary strength and rigidity.

An elongated polishing wheel assembly such as that shown in FIG. 3 willnot form streaks or lines on a workpiece, for the reason that there areno joints or discontinuities between adjacent polishing wheels. Thewheels are held in assembled relationship by the nut 114 and washer 112,and in addition the abrasive-bcaring, interleaved sheets 6, 5t) and 84frictionally engage each other, which thus tends to prohibit anysubstantial radial or lateral slippage which might cause unevenness inthe outer surface of the polishing wheel assembly. To further ensure theinterleaved sheets will remain properly assembled, a spot of suitableadhesive can be placed between the interleaved sheets on adjacent wheelsnear their associated cylindrical hubs to secure them together. Itshould be noted also that because the sheets 6, 5t and 84 arecoextensive with each other in the preferred embodiment of theinvention, the assembly will have the same density and firmness at allpoints along its length; this feature of the invention also contributesto the production of a smooth and even finished surface.

The sheets comprising the polishing wheels 2, 4 and 82 of the inventioncan be interleaved with each other by any desirable apparatus, or thiscan be done manually if desired. While the individual, radially directedsheets comprising each of the polishing wheels in the invention areshown to be secured together at their inner ends both by adhesive and anannular core ring, it is to be understood that other methods forsecuring said inner ends could be substituted without departing from theteachings of the invention. Further, it is to be understood that thesheets of the polishing wheels might vary somewhat from theconfigurations shown, without departing from the inventive conceptherein described.

The polishing wheels of the invention, depending upon the abrasive used,can be utilized to finish metals, plastic, 4

wood, and any other like materials. The elongated assembly of FIG. 3 isespecially suitable for finishing Wide surfaces, in that it avoids thedisadvantages of abrasive belts, While the even and unbroken surfacethereof ensures that there will be no streaks in the finished surface.

Thus, the assembly of FIG. 3 can be used to great advantage on flatmetallic surfaces, or on plywood sheets or other wood materials, toprovide a very smooth and even finished surface.

Obviously, many modifications and variations of the present inventionare possible in light of the above teachings. It is, therefore, to beunderstood that, within the scope of the appended claims, the inventionmay be practiced otherwise than as specifically described.

I claim:

1. A polishing wheel assembly, comprising: at least two polishing wheelsarranged in side-by-side relationship, each of said wheels including aplurality of radially extending sheets secured together at their innerends to define a hub, the radially outer portions of said sheets beingsubstantially wider than the inner portions thereof, and the radiallyouter portions of the sheets on one wheel being interleaved with theradially outer portions of the sheets on the other wheel.

2. A polishing wheel assembly as recited in claim 1, wherein theradially outer portions of the sheets on one wheel are substantiallycoextensive with the radially outer portions of the sheets on the otherwheel.

3. A polishing wheel assembly as recited in claim 1, wherein theradially outer portions of the sheets on one 8 wheel are substantiallywider than the radially outer portions of the sheets on the other wheel.

4. A polishing wheel assembly, comprising: a pair of polishing wheelsarranged in side-by-side relationship, each of said wheels including aplurality of radially extending sheets secured together at their innerends to define a hub, the radially outer portions of the sheets on atleast one of said wheels being substantially wider than the portions ofsaid sheets disposed adjacent the hub of said one wheel and projectingaxially beyond the hub of said one wheel toward the other of saidwheels, said radially outer sheet portions on said one wheel beinginterleaved with the radially outer portions of the sheets on the otherof said wheels.

5. A polishing wheel assembly as recited in claim 4, wherein theradially outer portions of the sheets on both of said wheels are widerthan the portions of said sheets disposed adjacent the hubs associatedtherewith, and wherein the radially outer portions on said wheelsproject toward and are interleaved with each other.

6. A polishing wheel assembly as recited in claim 5, wherein theradially outer sheet portions on one wheel are substantially coextensivewith the radially outer sheet portions on the other wheel with whichthey are interleaved.

7. A polishing wheel assembly as recited in claim 5, including at leastone additional polishing wheel disposed between the wheels of said pairin side-by-side relationship, said additional wheel including aplurality of radially extending sheets secured together at their innerends to define a hub, the radially outer portions of the sheets on saidadditional wheel projecting axially beyond the hub of said additionalwheel on both sides thereof and toward the sheets on the wheels of saidpair, the radially outer portions of the sheets on said additional wheelbeing interleaved with the radially outer portions of the sheets on bothwheels of said pair of wheels.

8. A polishing wheel structure for mounting in sidebyside relationshipwith a second similar polishing wheel structure, comprising: a pluralityof radially extending sheets secured together at their radially innerends to define a hub, the radially outer portions of said sheets havinga width substantially greater than the width of the radially inner endsof said sheets, and projecting axially of said wheel beyond at least oneend face of said hub a distance at least equal to about one-half thewidth of the radially inner ends of said sheets, said axially projectingsheet portions being of a size for interleaving in substantialoverlapping relationship with the axially oppositely directed outerportions of the sheets of a second similar polishing wheel mounted inside-by-side relationship.

9. A polishing wheel structure as recited in claim 8, wherein theradially outer portions of said sheets project beyond said one hub endface a distance about equal to the width of the radially inner ends ofsaid sheets at said hub.

10. A polishing wheel structure as recited in claim 8, wherein theradially outer portions of said sheets project axially of said wheel adistance at least equal to about one-half the width of the radiallyinner ends of said sheets beyond both end faces of said hub forinterleaving in substantial overlapping relationship with the sheets ofsimilar polishing wheels abutted against the opposite ends of said hub.

11. A polishing wheel structure as recited in claim 8, wherein theopposite end edges of said radially outer sheet portions lie in radialplanes that are parallel to each other.

12. A polishing wheel assembly, comprising: a pair of polishing wheelsarranged in side-by-side relationship, each of said wheels including aplurality of radially extending sheets secured together at their innerends to define a hollow cylindrical hub, the axial lengths of said hubsbeing about equal and the confronting end faces on said hubs beingdisposed immediately adjacent each other, the radially outer portions ofsaid sheets on both of said wheels having a width equal to about twicethe axial length of their associated hubs, the opposite, axially outerend edges of said outer portions lying in generally the same radialplanes as their associated axially outermost hub end faces, and theradially outer portions of the sheets on one wheel being interleavedwith the radially outer portions of the sheets on the other wheel.

13. A polishing wheel assembly as recited in claim 12, wherein the innerends of said sheets on each wheel are received on an annular core ringwhich passes through bores provided in said sheets.

14. A polishing wheel assembly as recited in claim 12, wherein the endfaces on each of said hubs have annular grooves therein, and includingadditionally an annular end plate mounted on each said end face, saidend plates each having an annular rib thereon received within itsassociated annular groove.

15. A polishing wheel assembly, comprising: a pair of polishing wheelsarranged in side-by-side, spaced apart relationship, each of said pairof wheels including a plurality of radially extending sheets securedtogether at their inner ends to define a hollow cylindrical hub, the

radially outer portions of the sheets on said pair of wheels being widerthan their associated hubs and projecting toward each other beyond theconfronting end faces of said hubs; at least one additional polishingwheel disposed between the polishing wheels of said pair in side-by-siderelationship, said additional wheel including a plurality of radiallydirected sheets secured together at their inner ends to define a hub,the opposite end faces of said hub on said additional wheel beingdisposed immediately adjacent the confronting end faces of the hub onsaid polishing wheels of said pair, the radially outer portions of thesheets on said additional Wheel projecting toward said pair of wheelsbeyond the and faces of the hub of said additional wheel a distanceabout equal to the axial length of the hub of the wheel toward whichthey project, the combined lengths of the confronting projecting outerportions of the sheets on the wheels of said pair being about equal tothe axial length of the hub of said additional wheel, and the sheets onall three of said wheels being interleaved.

16. A polishing wheel assembly, comprising: a shaft;

a pair of polishing wheels arranged in side-by-side, spaced apartrelationship on said shaft, each of said pair of wheels including aplurality of radially extending sheets secured together at their innerends to define a hollow cylindrical hub, the radially outer portions ofthe sheets on said pair of wheels being wider than their associated hubsand projecting toward each other beyond the confronting end faces ofsaid hubs; at least one additional polishing wheel on said shaftdisposed between the polishing Wheels of said pair in side-by-siderelationship, the external diameters of all of said polishing wheelsbeing the same, said additional wheel including a plurality of radiallydirected sheets secured together at their inner ends to define a hollowcylindrical hub, the opposite end faces of said hub on said additionalwheel being disposed immediately adjacent the confronting end faces ofthe hubs on said polishing wheels of said pair, the radially outerportions of the sheets on said additional Wheel projecting axiallytoward said pair of wheels beyond the end faces of the hub of saidadditional wheel a distance about equal to the axial length of the hubof the wheel toward which they project, the combined lengths of theconfronting projecting outer portions of the sheets on the Wheels ofsaid pair being about equal to the axial length of the hub of saidadditional wheel, and the sheets on all three of said wheels beinginterleaved.

17. A polishing wheel assembly as recited in claim 16, wherein the endfaces of the hubs on all of said wheels have annular grooves therein,and including additionally an end plate mounted on each hub end face,said end plates having openings therethrough to receive said shaft, andhaving annular ribs thereon which are received with the annular grooveson their associated. hub end faces.

References Cited UNITED STATES PATENTS 2,651,894 9/1953 Leggett 5l3372,802,315 8/1957 Block 51-337 2,907,145 10/1959 Hall 51-337 2,948,090 8/1960 Klingspor 5 1-337 3,206,786 8/1965 Sax 5l-337 X ROBERT C. RIORDON,Primary Examiner.

D. G. KELLY, Assistant Examiner.

1. A POLISHING WHEEL ASSEMBLY, COMPRISING: AT LEAST TWO POLISHING WHEELSARRANGED IN SIDE-BY-SIDE RELATIONSHIP, EACH OF SAID WHEELS INCLUDING APLURALITY OF RADIALLY EXTENDING SHEETS SECURED TOGETHER AT THEIR INNERENDS TO DEFINE A HUB, THE RADIALLY OUTER PORTIONS OF SAID SHEETS BEINGSUBSTANTIALLY WIDER THAN THE INNER PORTIONS THEREOF, AND THE RADIALLYOUTER PORTIONS OF THE SHEETS ON ONE WHEEL BEING INTERLEAVED WITH THERADIALLY OUTER PORTIONS OF THE SHEETS ON THE OTHER WHEEL.